There is no single genetic mechanism behind sex differences in different species and the existence of two sexes seems to have evolved multiple times independently in different evolutionary lineages. Patterns of sexual reproduction include

isogamous species with two or more mating types with gametes of identical form and behavior (but different at the molecular level),

oogamous species, which include humans in which the female gamete is very much larger than the male and has no ability to move. Oogamy is a form of anisogamy. There is an argument that this pattern was driven by the physical constraints on the mechanisms by which two gametes get together as required for sexual reproduction.

Plant reproductive morphology

Plant reproductive morphology is concerned with the physical form and structure (the morphology) of those parts of plants directly or indirectly concerned with sexual reproduction.

Among all living organisms, flowers, which are the reproductive structures of angiosperms, are the most varied physically and show a correspondingly great diversity in methods of reproduction. Plants that are not flowering plants (green algae, mosses, liverworts, hornworts, ferns and gymnosperms such as conifers) also have complex interplays between morphological adaptation and environmental factors in their sexual reproduction. The breeding system, or how the sperm from one plant fertilizes the ovum of another, depends on the reproductive morphology, and is the single most important determinant of the genetic structure of nonclonal plant populations. Christian Konrad Sprengel (1793) studied the reproduction of flowering plants and for the first time it was understood that the pollination process involved both biotic and abiotic interactions. Charles Darwin's theories of natural selection utilized this work to build his theory of evolution, which includes analysis of the coevolution of flowers and their insectpollinators.

Female (1933 film)

Plot

Alison Drake (Ruth Chatterton) is the wealthy owner and hard-driving, no-nonsense head of a large automobile company, inherited from her father. Her work has caused her to lose her youthful romanticism, and she has casual affairs with men, including her own employees.

Alison hosts a party at her mansion, but becomes fed up with the men out to either sell her things or marry her for her money. She dresses down and goes to an amusement park, where she picks up a man at a shooting gallery. They have fun together, but he refuses her offer to go home with him.

The next day, they meet again at her factory. To their mutual astonishment, he turns out to be Jim Thorne (George Brent), a gifted engineer she has ordered her underlings to hire away from her competition. Saying that she has no time now, Alison has him come to her mansion that night, supposedly to discuss his plans for the company in detail. She attempts to seduce him, but he rejects her as anything other than his employer.

There is no single genetic mechanism behind sex differences in different species and the existence of two sexes seems to have evolved multiple times independently in different evolutionary lineages. Patterns of sexual reproduction include

isogamous species with two or more mating types with gametes of identical form and behavior (but different at the molecular level),

oogamous species, which include humans in which the female gamete is very much larger than the male and has no ability to move. Oogamy is a form of anisogamy. There is an argument that this pattern was driven by the physical constraints on the mechanisms by which two gametes get together as required for sexual reproduction.

Latest News for: female journal

But the PED documents, released to the Journal late Tuesday in response to a request under the state’s open records law, allege there were no reports made by the school or the district to law enforcement or the PED. The documents reveal that the most recent report of alleged misconduct involved the female victim of the Dec....

UK females aged 50 to 70 are invited for mammograms every three years ... A study published yesterday in the BritishJournal of Cancer says this ‘false positive’ result raises the likelihood of a real diagnosis from 2 per cent to 4 per cent, and the increased risk lasts for 12 years....

Advertisement ...Raul Grijalva of wrongdoing in connection with a settlement he made with a female former staffer who accused him of being drunk and creating a hostile work environment ... The ethics panel said in a Dec ... After Grijalva wrote a Nov ... News from The Associated Press, and a taste of the great journalism produced by AP members and customers ... ....

Nevada became the first state in the US with an overall female majority in the Legislature on Tuesday when county officials in Las Vegas appointed two women to fill vacancies in the state Assembly... No state has previously had a female-majority or even a 50 percent-female ......

with an overall female majority in the Legislature on Tuesday when county officials in Las Vegas appointed two women to fill vacancies in the state Assembly... But they will hold 24 of 42 seats in the Assembly, comprising 57 percent in that chamber and giving women enough numbers to make the two chambers an overall female majority....

with an overall female majority in the Legislature on Tuesday when county officials in Las Vegas appointed two women to fill vacancies in the state Assembly... 55 percent in that chamber and giving women enough numbers to make the two chambers an overall female majority....

with an overall female majority in the Legislature on Tuesday when county officials in Las Vegas appointed two women to fill vacancies in the state Assembly... But they will hold 24 of 42 seats in the Assembly, comprising 57 percent in that chamber and giving women enough numbers to make the two chambers an overall female majority....

Now, they have found that the secret may lie in the second X chromosome, present in females. The study, conducted on mice, showed that females live longer than males, and that XX largely governs this trait in ageing mice ... "We've long wondered what causes female longevity," said Dena Dubal, Associate Professor at the UCSF....

Starting with its opening session in 2019, Nevada will be the first state in the nation to seat a majority-female Legislature ... Nevada is set to become the first state in the nation with an overall female-majority Legislature when its next session opens in the new year ... Nevada’s female population, according to the latest Census data, is 49.8%....

with an overall female majority in the Legislature on Tuesday when county officials in Las Vegas appointed two women to fill vacancies in the state Assembly... But they will hold 23 of 42 seats in the Assembly, comprising 55 percent in that chamber and giving women enough numbers to make the two chambers an overall female majority....

Now, they have found that the secret may lie in the second X chromosome, present in females. The study, conducted on mice, showed that females live longer than males, and that XX largely governs this trait in ageing mice ... "We’ve long wondered what causes female longevity. One can imagine nature has driven females to evolve this way....